I'm new to audiophile products, recently purchased the hd58x from the site (getting late June) and was wondering if this would be a good purchase. I just plan on using it with my PC (guessing it doesn't have a good dac). Or should I be considering a dac amp combo units? I really don't know

You want a DAC/amp combo.
While the 58X is easy enough to drive, using a proper DAC/amp extends and clarifies these beautifully. Really a very nice set of cans, worth investing in a moderately priced DAC/amp to do justice to owning them. You might be surprised at how much more you hear, and how much more clarity you experience with the proper rig. And you don’t have to kill your wallet to do so.
Read the reviews posted up in here by purchasers.
(I need to dig around in my archives to see if I can’t copy and paste up a review I did on this some little time ago on this unit before they added a device-specific review section)

dac/amp,
or if you want to be blown away. Get this, and when your wallet will let you, add in a DAC.
This is what i did for my daughters MAC (which supposedly has a great amp merely because of the chips they use) and then added a DAC later when I had an extra hundred dollars in a month.
Who knows you may like the audio world, and having that modularity allows you a little something.